RFR: Merge jfx17 [v2]

[Kevin Rushforth]

> Merge jfx17 branch into master.

Kevin Rushforth has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains six additional commits since the last revision:

 - Merge remote-tracking branch 'upstream/jfx17' into merge-jfx17-2021-07-16
 - 8268849: Update to 612.1 version of WebKit
   
   Co-authored-by: Arun Joseph <ajoseph at openjdk.org>
   Reviewed-by: kcr, jvos
 - 8269968: [REDO] Bump minimum version of macOS for x64 to 10.12
   
   Reviewed-by: jvos
 - 8269967: JavaFX should fail fast on macOS below minimum version
   
   Reviewed-by: jvos, arapte
 - 8268718: [macos] Video stops, but audio continues to play when stopTime is reached
   
   Reviewed-by: kcr, arapte
 - 8269597: Change JavaFX release version to 18
   
   Reviewed-by: pbansal, arapte

-------------

Changes:
  - all: https://git.openjdk.java.net/jfx/pull/577/files
  - new: https://git.openjdk.java.net/jfx/pull/577/files/b37fc96f..b37fc96f

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jfx&pr=577&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jfx&pr=577&range=00-01

  Stats: 0 lines in 0 files changed: 0 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jfx/pull/577.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/577/head:pull/577

PR: https://git.openjdk.java.net/jfx/pull/577